Flue gas, which is generated through the combustion of fossil fuel in a boiler of a thermoelectric power plant or the like using a large amount of fossil fuel, contains CO2. A method of removing and recovering CO2, which is contained in flue gas, by bringing flue gas, which contains CO2, into gas-liquid contact with an amine-based CO2 absorbent in a CO2 absorber so that CO2 is absorbed in the CO2 absorbent, and a method of storing the recovered CO2 without releasing the recovered CO2 into the atmosphere have been energetically studied.
For example, there is used a method of making the CO2 absorbent absorb CO2, which is contained in the flue gas, in the CO2 absorber to remove CO2 from the flue gas, regenerating the CO2 absorbent by releasing CO2, which is absorbed in the CO2 absorbent, in a regenerator, and reusing the CO2 absorbent to remove CO2 from flue gas by circulating the CO2 absorbent in the CO2 absorber again (for example, see Patent Literature 1). In this case, the CO2 absorbent absorbing CO2 releases CO2 by being heated with steam in the regenerator. As a result, highly-pure CO2 is recovered.